Liquid crystal display (LCD) panels are well known and widely used for visual presentations of many diverse forms of information. Somewhat unfortunately, however, LCD panels are typically made of very brittle substances, such as glass or ceramic, which can be easily broken, cracked, chipped or otherwise damaged. Consequently, during the manufacture or construction of a device which incorporates an LCD panel, care must be taken not to subject the LCD panel to forces which will cause such damage.
The potential for damage to an LCD panel is particularly acute when the LCD panel is electrically engaged with its operational electronic circuitry. To be effective, the connection between the LCD panel and its operational electronic circuitry needs to be reliable and robust. It happens, however, that in order to obtain effective connections, significant forces must be generated between the LCD panel and the electrical contacts which electronically engage the LCD to other circuitry. If improperly oriented, these forces can easily break or damage the LCD panel.
One solution sometimes used to minimize the damage that is likely to be caused during engagement of an electrical component, such as an LCD panel, with its cooperative electrical contacts involves using a connector which is operable with a so-called "zero insertion force". As generally used, the expression "zero insertion force" implies that the particular electrical component is prepositioned and stationary before any electrical contacts are urged into engagement with the component. Several devices have been proposed for this purpose. For example, U.S. Pat. No. 4,021,091 to Anholt et al., though not specifically concerned with LCD panel problems, discloses a zero force printed circuit board connector in which two rows of resilient contacts are mounted on opposite sides of a receiving slot. After the printed circuit board is positioned in the slot with zero force, the contacts are clamped onto the circuit board. In another example, U.S. Pat. No. 4,159,154 to Arnold discloses a zero insertion force connector which initially spreads opposed rows of contacts to create a slot into which a printed circuit board or similar electrical component can be inserted with zero force. Subsequently, the contacts of this device are released to clamp onto the board in the slot.
The present invention recognizes that the above-cited devices may be suitable for printed circuit boards or similar electrical components which have electrical contact points on directly opposite sides of the board or panel. These devices are not, however, necessarily suitable for LCD panels which have dual in-line (i.e. substantially parallel) rows of contact points that are located on the same side of the board. Further, the present invention recognizes that, although it is desirable to direct forces against an LCD panel which are effectively confined to a direction that is substantially perpendicular to the surface of the LCD in order to minimize damage to the LCD panel, this is not the only consideration. The present invention recognizes it is also desirable to have some "contact wipe", i.e. there should be some slight movement of the contact across the surface of the LCD panel during enagement of an electrical contact with an LCD panel, to ensure a proper electrical connection. The present invention further recognizes that many of the damage problems caused when forces are improperly applied to an LCD panel can be avoided if the LCD panel is prepositioned with zero force and then the panel itself is moved into engagement with appropriate electrical contacts.
In light of the above, the present invention provides a zero force connector for electrically engaging a dual in-line LCD panel with a printed circuit board which effectively orients impact forces on the LCD panel. The present invention also provides a zero force connector for electrically engaging a dual in-line LCD panel with a printed circuit board which establishes a robust connection between electrical components. Further, the present invention provides a zero insertion force connector for electrically engaging a dual in-line LCD panel with a printed circuit board which is simple to operate, relatively easy to manufacture, and comparatively cost-effective.